I have just done manual tool changes for years on the knee mill by placing tools in moving to Z zero and then cranking the knee to suit
Now however that I have a power drawbar (and plan on a toolchanger when I get time) on the Beaver Mill I have made a tool setter, this hooks directly to Mach and what I do is:
Place a probe in the checker and bring the checker down onto it, I then set my Z zero in Mach.
Next I place the next tool in the checker and bring it down onto the tool, press a button on my screen, it asks for tool height offset number and then when I enter that it puts the offset into the tool table, I repeat for all tools I will be using.
Once thats done I then put the probe in the spindle and touch off my material and zero the DRO, after that any tool I place in the spindle is offset to that zero position.
Pic of toolchecker and screen can be seen here.
http://www.machsupport.com/forum/index.php/topic,10331.80.htmlHood